The wide-spread use of touch-screen devices continues to explode. Smart phones, for example, are becoming lighter, thinner, but more powerful and capable on almost a daily basis. In addition, tablet electronics are also becoming ubiquitous, in part, because of the varying sizes that accommodate each user's particular needs. The input to the touch-screen on these devices is controlled by a series of finger gestures that manipulate images on the display. While there are different display technologies for interpreting the gesture inputs, one of the most common are capacitive touch-screens which take some of the charge stored in fingers to activate the screen to detect the gestures. In cold weather, however, when the user wears gloves to keep warm, capacitive touch-screens are difficult to operate. One solution to such a problem is the use of fabrics and other materials that are processed such that at least a portion of the surface of the glove is electrically conductive.
The use of electrically conductive fabrics and textiles is well known in the art. These materials can be found in a wide variety of uses, such as anti-static, anti-microbial, and functional cloth applications.
For example, Child U.S. Pat. No. 5,716,893 discloses a method of depositing a conductive polymer film on a textile fabric substrate. The method includes synthesizing a pyrrole compound having improved stability by the oxidative polymerization of an aqueous solution of a pyrrole compound in the presence of an oxidizing agent, dopant anion and a stabilizing agent.
Another example is Child et al. U.S. Pat. No. 6,001,749, which discloses a patterned conductive textile and a process for making the same. The process involves applying a durable finish to portions of the chosen substrate that inhibits the formation of a conductive polymer from forming on those areas.
Still another example is DeAngelis et al. U.S. Pat. No. 6,716,481, which discloses a process for making an electromagnetically conductive textile having a conductivity gradient through the thickness of the fabric. The process includes two or more superimposed webs of felt material with different electrical conductivities in order to create an conductivity gradient across the composite fabric's thickenss.
A further example of conductive materials can be found in Leto et al. International Publication No. WO 2010/141743, which discloses materials for use with capacitive touch-screens. The materials include textiles, leathers, non-woven materials, and leather-like materials impregnated with a composition including an electrically conductive agent and a binder. The described process includes curing coatings either under heat or air dried without heat.
Attempts at producing conductive material products have been somewhat successful. For example, Fownes Brothers & Co. has produced a line of touch-screen conductive gloves (see for example, www.urpowered.com) that provide the user with the ability to operate their touch-screen devices without removing the gloves, while the gloves themselves do not have the silver or metallic threads on the fingertips that many found to be undesirable. The conductive nature of these gloves, however, can degrades over time and use particularly due to conditions such as from wetness due to snow, ice, and laundering. This is due, at least in part, to the incompatibility between the process for making fabrics conductive versus making them water repellant. For example, if fabrics are already water repellant, it is very difficult to successfully treat to make them to make them conductive as well. Thus, it would be advantageous to provide high-quality water repellant conductive materials and methods for making the same that overcome the shortcomings of the current state-of-the art.